Gooding Claire E, Pinard Charlotte, Gries Regine, Devireddy Anand, Gries Gerhard
Department of Biological Sciences, Simon Fraser University, British Columbia, Canada V5A 1S6.
R Soc Open Sci. 2024 Jan 3;11(1):231355. doi: 10.1098/rsos.231355. eCollection 2024 Jan.
Ticks spend most of their life inhabiting leaf litter and detritus where they are protected from sun but preyed upon by ants. Ants secrete chemical communication signals to coordinate group tasks such as nest defence. Ticks that avoid ant semiochemicals-as indicators of ant presence-would reduce predation risk by ants. We tested the hypotheses that: (i) chemical deposits from the thatching ant deter blacklegged ticks, , (ii) deterrent semiochemicals originate from the ants' poison and/or Dufour's gland(s), and (iii) tick-deterrent semiochemicals serve as alarm-recruitment pheromone components in . In two-choice olfactometer bioassays, filter paper soiled with ant chemical deposits significantly deterred female and male ticks. Poison and Dufour's gland extracts deterred ticks in combination but not alone. Gas chromatographic-mass spectrometric analyses of gland extracts revealed formic acid as the major constituent in the poison gland and eight hydrocarbons as constituents in the Dufour's gland. Synthetic formic acid and hydrocarbons deterred ticks only when combined. workers sprayed both formic acid and hydrocarbons when distressed. A synthetic blend of these compounds elicited alarm-recruitment responses by in behavioural bioassays. All results combined indicate that ticks eavesdrop on the ants' communication system.
蜱虫一生的大部分时间都栖息在落叶层和碎屑中，在那里它们免受阳光照射，但会遭到蚂蚁的捕食。蚂蚁分泌化学通讯信号来协调群体任务，如巢穴防御。能够避开作为蚂蚁存在指示物的蚂蚁信息化学物质的蜱虫，可降低被蚂蚁捕食的风险。我们检验了以下假设：（i）茅草蚁的化学沉积物会驱赶黑腿蜱虫；（ii）驱避性信息化学物质源自蚂蚁的毒液和/或杜氏腺；（iii）蜱虫驱避性信息化学物质在蚂蚁中充当警报-召集信息素成分。在双选嗅觉仪生物测定中，被蚂蚁化学沉积物弄脏的滤纸显著驱赶雌性和雄性蜱虫。毒液和杜氏腺提取物单独使用时不能驱赶蜱虫，但联合使用时可以。对腺体提取物进行气相色谱-质谱分析发现，甲酸是毒腺中的主要成分，杜氏腺中的成分有八种碳氢化合物。合成的甲酸和碳氢化合物只有联合使用时才能驱赶蜱虫。蚂蚁受到惊扰时会喷洒甲酸和碳氢化合物。在行为生物测定中，这些化合物的合成混合物引发了蚂蚁的警报-召集反应。综合所有结果表明，蜱虫窃听了蚂蚁的通讯系统。
